Declaration as to Non-Infringement :

Under Section 105 of the Act, any person after the grant of publication of patent may institute a suit for a declaration as to non-infringement. For this the plaintiff must show that (a) he applied in writing to the patentee or his exclusive licensee for a written acknowledgement to the effect that the process used or the article produced by him does not infringe the patent and (b) patentee or the licensee refused or neglected to give such an acknowledgement. It is not necessary that the plaintiff must anticipate an infringement suit.